Generally a front subframe for supporting a suspension arm is formed below a front side frame in a front portion of a vehicle. The front subframe includes a rear cross member extending in the vehicle width direction, a pair of left and right side members (front side members) extending forward of the vehicle from the rear cross member, and a front cross member for connecting front ends of the paired left and right side members in the vehicle width direction.
In recent years, there is a demand for providing a structure against a small overlap collision in a front portion of a vehicle. For example, Japanese Unexamined Patent Publication No. 2013-212757 (hereinafter, referred to as Patent Literature 1) discloses a structure, in which a projecting portion projecting outward in the vehicle width direction is not formed on a front subframe, but is formed on a front portion of a front side frame. The projecting portion is formed in such a manner that a lateral surface of the projecting portion on the outer side in the vehicle width direction is inclined inward in the vehicle width direction toward the rear side of a vehicle body in a plan view of the vehicle. Further, the projecting portion is disposed at a position where a power unit and the projecting portion overlap in the vehicle front-rear direction.
In the structure disclosed in Patent Literature 1, since the front side frame is bent inward in the vehicle width direction via the projecting portion when a small overlap collision occurs, it is possible to generate a moment for moving a front portion of a vehicle body in a sideways direction (allowing a front portion of a vehicle body to escape from a collision object) by causing the bent front side frame to press the power unit. However, in the structure disclosed in Patent Literature 1, since the front subframe does not include a front cross member, rigidity may be insufficient, and vibration is likely to occur when a member substantially equivalent to the projecting portion is formed on the front subframe.
Japanese Unexamined Patent Publication No. 2016-141282 (hereinafter, referred to as Patent Literature 2) discloses a front subframe structure including a pair of left and right side members, a front cross member for connecting from ends of the paired left and right side members in the vehicle width direction, a sub crash can having a trapezoidal shape in a plan view and connected to the front end of each side member via a set plate and a mounting plate, and a branching member for connecting a rear surface of a portion of a base portion of the sub crash can on the outer side in the vehicle width direction and a front portion of each side member in an obliquely opposite relationship.
In the structure disclosed in Patent Literature 2, it is possible to bend the side member inward in the vehicle width direction by transmitting a load generated when a small overlap collision occurs to a side member on the rear side via the branching member, after the load is received by the trapezoidal sub crash can.
However, in the structure disclosed in Patent Literature 2, a pair of left and right mounting portions for mounting the front subframe to a vehicle body are disposed at positions coincident with both ends of the front cross member. Therefore, it is necessary to set the position of the front cross member to a relatively forward position in order to secure the aforementioned positional relationship. On the other hand, it is general that an auxiliary component such as a radiator is disposed on the front side of a front cross member. However, when an auxiliary component is attempted to be disposed while securing a sufficient space for mounting and dismounting the auxiliary component on the front side of the front cross member, the auxiliary component and peripheral parts thereof may be disposed on the front side as a whole. This may increase an overhang dimension of the vehicle (a size of a portion located on the front side with respect to front wheels). As described above, in the structure disclosed in Patent Literature 2, it is difficult to simultaneously satisfy both requirements on a layout of an auxiliary component (securing a space for mounting and dismount an auxiliary component), and shortening an overhang dimension.